Help with Wheel & Tire questions

[SLACKER]

I have just purchased a 1995 E350 4x4 Sportsmobile with Eagle Alloy aluminum wheels with 285/75/16 tires. The prior owner has told me that the vehicle weighs in at 10,000 lbs loaded. I will be doing extensive travel fully loaded with an additional 350 lbs off the rear (small motorcycle etc) through Latin America with some offroading. My questions are ;

The current tires are 32-33" diameter and an all-season tread. I want to at least replace them with a more aggressive tread tire (thinking something like BFG T/A KO2). I am considering going to a larger tire size as well. Either same diameter but wider (305/70/16) or taller 35's (315/75/16) Besides dealing with constraints of the wheel wells are there other concerns I should consider? ie Should I worry about added weight/dia/forces causing front end components to wear more rapidly? Universals having more strain due to slightly sharper angles if I go with 35's?
I believe the vehicle has a total of 5" lift with Agile's RIP suspension set up installed BTW
Any advice on this would be greatly appreciated. The prior owner (Scotty86)has been tremendously helpful with me on a multitude of questions but neither of us know much about these topics
Thanks.........

[rallypanam]

Which wheels? I also have Eagle Alloys but mine are rated at 3420lbs each...

American Eagle Wheels

[SLACKER]

Originally Posted by rallypanam

Which wheels? I also have Eagle Alloys but mine are rated at 3420lbs each...

American Eagle Wheels

I had some bad info regarding max load on the Eagle Alloys on Summit racing website. I just referred to the Eagle site and indeed the wheels are rated at 3420 lbs. That's a relief!
It looks like my only question remaining is on the tires
Thanks rallypanam!

[daveb]

All I can say is with my 2006 SMB front end, I doubt I could have squeezed in much over the 285-75-16 that they supplied. After I had Deaver Spring do their thing I gained enough lift to go with taller tires but still, when I pull the sway bar disconnects, I have to be careful of the Bushwhacker's in a sharp turn going into a deep rut or similar. The tire will hit and rip up the back/inside wheel well and grab the Bushwhacker. They are expensive.

[rallypanam]

Wait, you bought 86scotty's van? How did I not hear of this?

As for tires, it's a Quigley with RIP.. They are all a little different, but you're close to max tire size.. You may be able to go larger, but you also may need to cut the rear of the wheel well to get clearance.

[SLACKER]

Yes, I am buying 86scotty's Van...........aka "Rusty"...........and I feel very lucky!
He is actually making some mods to the vehicle before I take possession. Most of my recent 4x4 experience is with a Land Rover Defender 110 TD5 (which I decided was too small for my intended use). Oddly enough the Defender also has 285/75/16's as standard setup.
As for the tires; we have a shop that is willing to mount some 315/75/16's (35") to see how well they fit at least stationary in the shop. I had hoped to get some additional ground clearance but am not interested in making any radical changes or additional body lift to accomplish that. I assume trimming the wheel wells is not a huge project but really don't know any hard facts at this point. At the very least a more aggressive tire is in order....
Thanks for your input!

[JoeH]

What's the gear ratio on the differentials? No hard set rules here but generally:

Stock tire: 3.73
35s: 4.10
37s: 4.30 or 4.56

Besides the clearance issues with the Quigley are you going for a stock like feel? Anything lower you will gain some low end. 3.73 with 35" and you'll have longer legs for the freeway but not as good for offroad and the transmission may struggle to stay in overdrive.

Here's an online calculators:
4x4 related Calculators, Crawl Ratio, Gears Tires Sizes, etc..

[86Scotty]

The van is an EFI 460 gas with 3.73 from the factory.

[SLACKER]

Power is 460 gas engine with 3.73 ratio. I understand the concerns of gearing and how it relates to tire diameter but not having driven the rig much (86scotty is still working on it)I am unfamiliar with it's current shifting/power characteristics. Having said that I should probably wait until I drive it more with a good load before deciding whether to go with 35's which would change overall gearing by +/- 5%.
Any opinions on 285/75 vs 305/70' s? I believe the dia will remain unchanged but the 305's would have a wider tread?

[JoeH]

Originally Posted by SLACKER

Any opinions on 285/75 vs 305/70' s? I believe the dia will remain unchanged but the 305's would have a wider tread?

It will look cooler with the 305s and even more so with the 315s. Maybe a bit more stability (debatable) and not as good in snow. From my perspective not sure it matters really. There are not many tire options for 305s but lots at 33".

Whatever you do go E rated. One reason a lot of the guys ran 305s back in the 2000s is SMB was spec'ing BF Goodrich 305s on a lot of the vans. But in D rated and there were a lot of failures. Tire delamination and that sort of thing.

You asked what else and I would suggest new ball joints on a long trip like what your planning. But probably easy enough to source along the way as well.